COPD

People with COPD are inactive compared with age- and sex-matched healthy individuals. 1 This is an important concern because low levels of physical activity have been associated with worse health out-comes, including all-cause mortality. 2-4 Although on average, individuals with COPD are inactive, there is considerable variation within study samples regard-ing the number of steps and time spent walking each day. 1,5-7 The capacity to identify those who are the most sedentary would allow clinicians to use a tar-geted approach when implementing therapies that increase physical activity. Earlier work has demon-strated a strong relationship between 6-min walk distance (6MWD) and measures of physical activity during daily life obtained using accelerometers, 1,8,9 suggesting that tests of exercise capacity may provide information regarding daily activity. However, no study to our knowledge has examined the relation-ships between 6MWD and incremental shuttle walk distance (ISWD) and objective measures of average daily energy expenditure (DEE). Further, it is unclear whether performance during the 6-min walk test (6MWT) and incremental shuttle walk test (ISWT) is more closely associated with DEE than peak oxygen uptake ( V o 2 peak), a standard measure of aerobic capacity. 10 Such information will help clinicians to identify which tests of exercise capacity provide infor-mation regarding activity in the home environment. In addition to understanding the extent to which tests of exercise capacity may provide information Background: The aims of this study were to determine which tests of exercise capacity relate to average daily energy expenditure (DEE) and to quantify aerobic reserve during daily life in people with COPD. Methods: A cross-sectional study was undertaken in 26 people with COPD (16 men; FEV 1, 50 % 16%). Six-min walk distance (6MWD) and incremental shuttle walk distance (ISWD) measures were collected, and peak oxygen uptake ( V O 2 peak) was measured during a symp-tom-limited ramp cycle ergometry test. The SenseWear Armband was worn during the waking hours for 4.4 1.1 days to measure DEE. The intensity at which activities of daily living were undertaken was expressed as a percentage of V O 2 peak